more arc features (#13098)

* config update
* ARC now supports 'repr' and 'new' with finalizers is supported

compiler/ccgexprs.nim

@@ -2172,7 +2172,11 @@ proc genMagicExpr(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
       genRepr(p, e, d)
   of mOf: genOf(p, e, d)
   of mNew: genNew(p, e)
-  of mNewFinalize: genNewFinalize(p, e)
+  of mNewFinalize:
+    if optTinyRtti in p.config.globalOptions:
+      genNew(p, e)
+    else:
+      genNewFinalize(p, e)
   of mNewSeq: genNewSeq(p, e)
   of mNewSeqOfCap: genNewSeqOfCap(p, e, d)
   of mSizeOf:

compiler/nim.cfg

@@ -1,6 +1,7 @@
 # Special configuration file for the Nim project
 
 hint[XDeclaredButNotUsed]:off
+hint[Link]:off
 
 define:booting
 define:nimcore

compiler/semmagic.nim

@@ -383,6 +383,35 @@ proc semUnown(c: PContext; n: PNode): PNode =
   # little hack for injectdestructors.nim (see bug #11350):
   #result[0].typ = nil
 
+proc turnFinalizerIntoDestructor(c: PContext; orig: PSym): PSym =
+  # We need to do 2 things: Replace n.typ which is a 'ref T' by a 'var T' type.
+  # Replace nkDerefExpr by nkHiddenDeref
+  # nkDeref is for 'ref T':  x[].field
+  # nkHiddenDeref is for 'var T': x<hidden deref [] here>.field
+  proc transform(n: PNode; old, fresh: PType; oldParam, newParam: PSym): PNode =
+    result = shallowCopy(n)
+    if sameTypeOrNil(n.typ, old):
+      result.typ = fresh
+    if n.kind == nkSym and n.sym == oldParam:
+      result.sym = newParam
+    for i in 0 ..< safeLen(n):
+      result[i] = transform(n[i], old, fresh, oldParam, newParam)
+    #if n.kind == nkDerefExpr and sameType(n[0].typ, old):
+    #  result =
+
+  result = copySym(orig)
+  result.flags.incl sfFromGeneric
+  let origParamType = orig.typ[1]
+  let newParamType = makeVarType(result, origParamType.skipTypes(abstractPtrs))
+  let oldParam = orig.typ.n[1].sym
+  let newParam = newSym(skParam, oldParam.name, result, result.info)
+  newParam.typ = newParamType
+  # proc body:
+  result.ast = transform(orig.ast, origParamType, newParamType, oldParam, newParam)
+  # proc signature:
+  result.typ = newProcType(result.info, result)
+  result.typ.addParam newParam
+
 proc magicsAfterOverloadResolution(c: PContext, n: PNode,
                                    flags: TExprFlags): PNode =
   ## This is the preferred code point to implement magics.
@@ -447,6 +476,8 @@ proc magicsAfterOverloadResolution(c: PContext, n: PNode,
     # Make sure the finalizer procedure refers to a procedure
     if n[^1].kind == nkSym and n[^1].sym.kind notin {skProc, skFunc}:
       localError(c.config, n.info, "finalizer must be a direct reference to a proc")
+    elif optTinyRtti in c.config.globalOptions:
+      bindTypeHook(c, turnFinalizerIntoDestructor(c, n[^1].sym), n, attachedDestructor)
     result = n
   of mDestroy:
     result = n

compiler/sempass2.nim

@@ -758,6 +758,7 @@ proc track(tracked: PEffects, n: PNode) =
       if n[1].typ.len > 0:
         createTypeBoundOps(tracked, n[1].typ.lastSon, n.info)
         createTypeBoundOps(tracked, n[1].typ, n.info)
+        # new(x, finalizer): Problem: how to move finalizer into 'createTypeBoundOps'?
 
     if a.kind == nkSym and a.sym.name.s.len > 0 and a.sym.name.s[0] == '=' and
           tracked.owner.kind != skMacro:

lib/system.nim

@@ -250,7 +250,7 @@ const ThisIsSystem = true
 proc internalNew*[T](a: var ref T) {.magic: "New", noSideEffect.}
   ## Leaked implementation detail. Do not use.
 
-when not defined(gcDestructors):
+when true:
   proc new*[T](a: var ref T, finalizer: proc (x: ref T) {.nimcall.}) {.
     magic: "NewFinalize", noSideEffect.}
     ## Creates a new object of type ``T`` and returns a safe (traced)
@@ -2197,6 +2197,7 @@ proc insert*[T](x: var seq[T], item: T, i = 0.Natural) {.noSideEffect.} =
       defaultImpl()
   x[i] = item
 
+when not defined(nimV2):
   proc repr*[T](x: T): string {.magic: "Repr", noSideEffect.}
     ## Takes any Nim variable and returns its string representation.
     ##
@@ -3555,6 +3556,9 @@ template unlikely*(val: bool): bool =
 import system/dollars
 export dollars
 
+when defined(nimV2):
+  import system/repr_v2
+  export repr_v2
 
 const
   NimMajor* {.intdefine.}: int = 1
@@ -4218,6 +4222,9 @@ type
   NimNode* {.magic: "PNimrodNode".} = ref NimNodeObj
     ## Represents a Nim AST node. Macros operate on this type.
 
+when defined(nimV2):
+  proc repr*(x: NimNode): string {.magic: "Repr", noSideEffect.}
+
 macro lenVarargs*(x: varargs[untyped]): int {.since: (1, 1).} =
   ## returns number of variadic arguments in `x`
   proc lenVarargsImpl(x: NimNode): NimNode {.magic: "LengthOpenArray", noSideEffect.}

lib/system/repr_v2.nim

@@ -0,0 +1,170 @@
+proc repr*(x: int): string {.magic: "IntToStr", noSideEffect.}
+  ## repr for an integer argument. Returns `x`
+  ## converted to a decimal string.
+
+proc repr*(x: int64): string {.magic: "Int64ToStr", noSideEffect.}
+  ## repr for an integer argument. Returns `x`
+  ## converted to a decimal string.
+
+proc repr*(x: float): string {.magic: "FloatToStr", noSideEffect.}
+  ## repr for a float argument. Returns `x`
+  ## converted to a decimal string.
+
+proc repr*(x: bool): string {.magic: "BoolToStr", noSideEffect.}
+  ## repr for a boolean argument. Returns `x`
+  ## converted to the string "false" or "true".
+
+proc repr*(x: char): string {.magic: "CharToStr", noSideEffect.}
+  ## repr for a character argument. Returns `x`
+  ## converted to a string.
+  ##
+  ## .. code-block:: Nim
+  ##   assert $'c' == "c"
+
+proc repr*(x: cstring): string {.magic: "CStrToStr", noSideEffect.}
+  ## repr for a CString argument. Returns `x`
+  ## converted to a string.
+
+proc repr*(x: string): string {.magic: "StrToStr", noSideEffect.}
+  ## repr for a string argument. Returns `x`
+  ## as it is. This operator is useful for generic code, so
+  ## that ``$expr`` also works if ``expr`` is already a string.
+
+proc repr*[Enum: enum](x: Enum): string {.magic: "EnumToStr", noSideEffect.}
+  ## repr for an enumeration argument. This works for
+  ## any enumeration type thanks to compiler magic.
+  ##
+  ## If a `repr` operator for a concrete enumeration is provided, this is
+  ## used instead. (In other words: *Overwriting* is possible.)
+
+template repr(t: typedesc): string = $t
+
+proc isNamedTuple(T: typedesc): bool =
+  # Taken from typetraits.
+  when T isnot tuple: result = false
+  else:
+    var t: T
+    for name, _ in t.fieldPairs:
+      when name == "Field0":
+        return compiles(t.Field0)
+      else:
+        return true
+    return false
+
+proc repr*[T: tuple|object](x: T): string =
+  ## Generic `repr` operator for tuples that is lifted from the components
+  ## of `x`. Example:
+  ##
+  ## .. code-block:: Nim
+  ##   $(23, 45) == "(23, 45)"
+  ##   $(a: 23, b: 45) == "(a: 23, b: 45)"
+  ##   $() == "()"
+  when T is object:
+    result = $typeof(x)
+  else:
+    result = ""
+  result.add '('
+  var firstElement = true
+  const isNamed = T is object or isNamedTuple(T)
+  when not isNamed:
+    var count = 0
+  for name, value in fieldPairs(x):
+    if not firstElement: result.add(", ")
+    when isNamed:
+      result.add(name)
+      result.add(": ")
+    else:
+      count.inc
+    when compiles($value):
+      when value isnot string and value isnot seq and compiles(value.isNil):
+        if value.isNil: result.add "nil"
+        else: result.addQuoted(value)
+      else:
+        result.addQuoted(value)
+      firstElement = false
+    else:
+      result.add("...")
+      firstElement = false
+  when not isNamed:
+    if count == 1:
+      result.add(',') # $(1,) should print as the semantically legal (1,)
+  result.add(')')
+
+proc repr*[T: (ref object)](x: T): string =
+  ## Generic `repr` operator for tuples that is lifted from the components
+  ## of `x`.
+  if x == nil: return "nil"
+  result = $typeof(x) & "("
+  var firstElement = true
+  for name, value in fieldPairs(x[]):
+    if not firstElement: result.add(", ")
+    result.add(name)
+    result.add(": ")
+    when compiles($value):
+      when value isnot string and value isnot seq and compiles(value.isNil):
+        if value.isNil: result.add "nil"
+        else: result.addQuoted(value)
+      else:
+        result.addQuoted(value)
+      firstElement = false
+    else:
+      result.add("...")
+      firstElement = false
+  result.add(')')
+
+proc collectionToRepr[T](x: T, prefix, separator, suffix: string): string =
+  result = prefix
+  var firstElement = true
+  for value in items(x):
+    if firstElement:
+      firstElement = false
+    else:
+      result.add(separator)
+
+    when value isnot string and value isnot seq and compiles(value.isNil):
+      # this branch should not be necessary
+      if value.isNil:
+        result.add "nil"
+      else:
+        result.addQuoted(value)
+    else:
+      result.addQuoted(value)
+  result.add(suffix)
+
+proc repr*[T](x: set[T]): string =
+  ## Generic `repr` operator for sets that is lifted from the components
+  ## of `x`. Example:
+  ##
+  ## .. code-block:: Nim
+  ##   ${23, 45} == "{23, 45}"
+  collectionToRepr(x, "{", ", ", "}")
+
+proc repr*[T](x: seq[T]): string =
+  ## Generic `repr` operator for seqs that is lifted from the components
+  ## of `x`. Example:
+  ##
+  ## .. code-block:: Nim
+  ##   $(@[23, 45]) == "@[23, 45]"
+  collectionToRepr(x, "@[", ", ", "]")
+
+proc repr*[T, U](x: HSlice[T, U]): string =
+  ## Generic `repr` operator for slices that is lifted from the components
+  ## of `x`. Example:
+  ##
+  ## .. code-block:: Nim
+  ##  $(1 .. 5) == "1 .. 5"
+  result = $x.a
+  result.add(" .. ")
+  result.add($x.b)
+
+proc repr*[T, IDX](x: array[IDX, T]): string =
+  ## Generic `repr` operator for arrays that is lifted from the components.
+  collectionToRepr(x, "[", ", ", "]")
+
+proc repr*[T](x: openArray[T]): string =
+  ## Generic `repr` operator for openarrays that is lifted from the components
+  ## of `x`. Example:
+  ##
+  ## .. code-block:: Nim
+  ##   $(@[23, 45].toOpenArray(0, 1)) == "[23, 45]"
+  collectionToRepr(x, "[", ", ", "]")

tests/destructor/tfinalizer.nim

@@ -0,0 +1,25 @@
+discard """
+  cmd: "nim c --gc:arc $file"
+  output: '''Foo(field: "Dick Laurent", k: ka, x: 0.0)
+Dick Laurent is dead'''
+"""
+
+type
+  Kind = enum
+    ka, kb
+  Foo = ref object
+    field: string
+    case k: Kind
+    of ka: x: float
+    of kb: discard
+
+#var x = Foo(field: "lovely")
+proc finalizer(x: Foo) =
+  echo x.field, " is dead"
+
+var x: Foo
+new(x, finalizer)
+x.field = "Dick Laurent"
+# reference to a great movie. If you haven't seen it, highly recommended.
+
+echo repr x